docs: def _handle_response(self):
          """
          Handles response after the redirect to GitHub. This response
          determines if the user has allowed the this application access. If we
          were then we send a POST request for the access_key used to
          authenticate requests to GitHub.
  
          """
          _logger.debug("Handling response from GitHub")
          params = {
              'code': request.args.get('code'),
              'client_id': self.client_id,
              'client_secret': self.client_secret
          }
          url = self.auth_url + 'access_token'
          _logger.debug("POSTing to %s", url)
          _logger.debug(params)
          response = self.session.post(url, data=params)
          data = parse_qs(response.content)
          _logger.debug("response.content = %s", data)
          for k, v in data.items():
              if len(v) == 1:
                  data[k] = v[0]
          token = data.get(b'access_token', None)
          if token is not None:
              token = token.decode('ascii')
          return token